Disposal of persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCB) contaminated material is an on-going problem for many environmental agencies. Until recently, POP material was disposed of in landfill or destructed. Destruction POP materials such as PCBs is problematic in that toxic side products, namely furan and dioxin are produced, largely because of incomplete combustion of the PCBs. Both disposal processes, however, are unsatisfactory because they release harmful breakdown products into the atmosphere, the soil or into the water table. Clean up of PCB contaminated soil and water supplies is therefore of high importance. One particularly important disposal problem concerns oil that is contaminated with PCBs. PCB contaminated oil has historically been incinerated, but oftentimes the incineration process is incomplete and results in only partial thermal breakdown of the PCB into the aforesaid breakdown products, by destructing only 99.99% of the contaminants. To date no safe and effective disposal method for PCB-contaminated oil is available.
U.S. Pat. No. 5,435,258, issued to Piette on Jul. 25, 1995 for “Method and Apparatus for Regenerating Desiccants” discloses a rotating perforated drum that contains an amount of a contaminated desiccant. The drum rotates with the contaminated desiccant tumbling therein and is subjected to combustion flames playing on its under side, thus burning the oil off the desiccant as the drum rotates. In this instance, the desiccant is the carrier for the contaminant and whilst this simple operation appears to work well for this specific application, it would be inappropriate for use with oil contaminated with PCBs, since the destruction process would be insufficient to destroy the toxic side product of PCB destruction and therefore would release toxic products into the atmosphere. Furthermore, neither the temperature nor the time of combustion would be adequate for the purpose of effecting complete thermal breakdown of the PCB.
Thus there is an urgent need for a safe and efficient apparatus and process for destruction of POPs, including oils contaminated with PCB.